[gmx-users] What is wrong with enthalpy?

[Igor Shchechkin]

Dear Gromacs users,

I have changed from 4.5.3 to 4.6.5 version and then continued
simulation of Protein+Ligands+water+ions system, having used new
created .tpr file and .cpt file produced by the latter run of 4.5.3
version. All went normally, but when I evaluated enthalpy, it appeared
to jump from -1.16e6 to -0.67e6.
(Earlier I encountered such phenomenon when changed from 4.5.3 to 4.5.5)
What is the cause of this?

Best regards,
Igor Shchechkin